Title: Probing Stress States in Silicon Nanowires During Electrochemical Lithiation Using In Situ Synchrotron X-Ray Microdiffraction

Abstract

Silicon is considered as a promising anode material for the next-generation lithium-ion battery (LIB) due to its high capacity at nanoscale. However, silicon expands up to 300% during lithiation, which induces high stresses and leads to fractures. To design silicon nanostructures that could minimize fracture, it is important to understand and characterize stress states in the silicon nanostructures during lithiation. Synchrotron X-ray microdiffraction has proven to be effective in revealing insights of mechanical stress and other mechanics considerations in small-scale crystalline structures used in many important technological applications, such as microelectronics, nanotechnology, and energy systems. In the present study, an in situ synchrotron X-ray microdiffraction experiment was conducted to elucidate the mechanical stress states during the first electrochemical cycle of lithiation in single-crystalline silicon nanowires (SiNWs) in an LIB test cell. Morphological changes in the SiNWs at different levels of lithiation were also studied using scanning electron microscope (SEM). It was found from SEM observation that lithiation commenced predominantly at the top surface of SiNWs followed by further progression toward the bottom of the SiNWs gradually. The hydrostatic stress of the crystalline core of the SiNWs at different levels of electrochemical lithiation was determined using the in situ synchrotron X-raymore » microdiffraction technique. We found that the crystalline core of the SiNWs became highly compressive (up to -325.5 MPa) once lithiation started. In conclusion, this finding helps unravel insights about mechanical stress states in the SiNWs during the electrochemical lithiation, which could potentially pave the path toward the fracture-free design of silicon nanostructure anode materials in the next-generation LIB.« less

Authors:

Ali, Imran ^[1]; Tippabhotla, Sasi Kumar ^[1]; Radchenko, Ihor ^[1]; Al-Obeidi, Ahmed ^[2]; Stan, Camelia V. ^[3]; Tamura, Nobumichi ^[3]; Budiman, Arief Suriadi ^[1]

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+ Show Author Affiliations

1. Singapore Univ. of Technology and Design (SUTD), Singapore (Singapore). Xtreme Materials Lab. (XML), Engineering Product Development (EPD) Pillar
2. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS)

Publication Date:

Wed Apr 04 00:00:00 EDT 2018

Research Org.:

Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1440962

Grant/Contract Number:  

AC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

Frontiers in Energy Research

Additional Journal Information:

Journal Volume: 6; Journal Issue: APR; Journal ID: ISSN 2296-598X

Publisher:

Frontiers Research Foundation

Country of Publication:

United States

Language:

English

Subject:

25 ENERGY STORAGE; in situ; lithium-ion battery; single-crystalline silicon nanowires; lithiation; stress; deformation; synchrotron X-ray microdiffraction